If the devices are in the same security level, then you do not need the transition. By setting an association you set a direct link between a button and a light. So you can turn a light on/off and dim without needing flows. The below description sounds difficult, but once you see how it’s done its usually quite simple.
You need to set the lamp ID in the associations of the button. Fitst you look in the developer page above what the ID is for the light (first number in the list). The button manual will explain which association groups are for what button.
In Homey you go to the advanced options of the button device to set the ID in the right association group. Depending on wether the light is a multichannel device or not, you will either have to put the button ID in the right group, or the button id and the channel.
For example, if the ID is 12 you must use either 12 or 12.1 of the light is the first channel. I’d start with the ID, but for instance Fibaro requires the .1 behind it. For instance, switches that can switch two lights have channel 1 and channel 2 for that device ID.
Also important to know: buttons are usually battery operated. Those devices enter a sleep mode to save batteries. In order to save the settings to the button, you need to wake the button right before you save the settings. The button manual will also explain how that works for your button.
Below is a screenshot of one of my 4 button remote (Heat-it push 4), where the upper two buttons operate light id 76 and the lower two buttons operate the light with id 75. Because I use Fibaro dimmers that require a channel I use 76.1 and 75.1 as ID’s. Group 1 is for the controller, Homey always has ID 1. This setting is so Homey also is properly linked to the button, this was set during pairing and needs to remain unchanged.
Before I press save, these buttons require me to press the upper two buttons simultaneously for 3 seconds to wake the device. Then I press the checkmark in the above right corner.